Nuki has quickly become a popular smart home brand for budget-minded buyers, offering smart connected locks that work with European-style door mechanisms. While it makes the Nuki Opener for individual apartment door buzzers, the company is expanding its support for apartment dwellers and owners with the Nuki Box.

Previously available only to some buildings in Germany and Austria, Nuki (say it like "new key") is now opening a direct purchase option for the Box. It installs behind a multi-user intercom panel at an apartment building's front door, providing phone-based access for occupants and visitors just like a standard Nuki lock.

The reason this is a big deal is that it's easy to retrofit into an old building merely by plugging it into the existing wiring system. By using an integrated 2G eSIM for a mobile connection and BLE for access, it doesn't even require a modern building-wide network. (Europe still uses 2G systems for machine-to-machine services, just like this one.) The Box won't interfere with the conventional locking mechanism. Access to the building's front door can be given to residents' phones (or a BLE-equipped Nuki Fob) even if they don't have their own Nuki lock hardware. When installed and connected to a Nuki Bridge and lock on the tenant's apartment door, the Nuki Box can allow users to grant access remotely via the app.

While it needs the building's owner and an electrician to install, the 349€ price tag is tiny for something that adds a modern convenience to a building full of residents. The Nuki Box is shipping now "to everyone," according to the company's blog—presumably that means everyone in its supported area, across Germany, Austria, Switzerland, France, Italy, the Netherlands, and Spain. You might be able to find it at retailers in other European countries, too.